collaborators

6 papers

astro-ph.GA2026

Probing the IMF in the Early Universe -- Direct measurements in the Boötes I UFD with JWST/NIRCam

Keyi Ding, Mario Gennaro, Roberto J. Avila +20

The dependence of the stellar initial mass function (IMF) on star-formation environment, particularly at low metallicities and high redshifts, remains poorly constrained. Ultra-fai…

astro-ph.CO2026

SKYSURF-11: A New Zodiacal Light Model Optimized for Optical Wavelengths

Rosalia O'Brien, Richard G. Arendt, Rogier A. Windhorst +15

We present an improved zodiacal light model, optimized for optical wavelengths, using archival Hubble Space Telescope (HST) imaging from the SKYSURF program. The Kelsall et al. 199…

astro-ph.GA2026

On the Use of Field RR Lyrae as Galactic Probes -- VIII. Early Formation of the Galactic Spheroid

G. Bono, V. F. Braga, M. Fabrizio +54

We introduce a new photometric catalog of RR Lyrae variables (RRLs, 300,000) mainly based on data available in public datasets. We also present the largest and most homogeneo…

astro-ph.SR2025

An excess of luminous white dwarfs in the peculiar Galactic globular cluster NGC 2808

Laksh Gupta, Samyaday Choudhury, Annalisa Calamida +2

We study the white dwarf (WD) cooling sequence of the Galactic Globular Cluster (GGC) NGC 2808 by using deep near-UV data from the Hubble Space Telescope and theoretical models, to…

astro-ph.SR2025

Betelgeuse's Buddy: X-Ray Constraints on the Nature of Ori B

Anna J. G. O'Grady, Brendan O'Connor, Jared A. Goldberg +8

The d Long Secondary Period of Betelgeuse's optical lightcurve and radial velocity motivated the prediction of a low-mass stellar companion, expected to be at maximal a…

astro-ph.SR2025

Betelgeuse, Betelgeuse, Betelgeuse, Betel-buddy? Constraints on the dynamical companion to Orionis from HST

Jared A. Goldberg, Anna J. G. O'Grady, Meridith Joyce +10

Recently, two independent analyses have asserted that the cause of the Long Secondary Period (LSP) observed in the variability spectrum of our nearest red supergiant, Betelgeuse ($…